1. Field of the Invention
The present invention relates to an electronic device having a capability of communicating with a server that provides time information service via a communication medium such as a network. The present invention also relates to a device, information processing apparatus, and an image forming apparatus, having a capability of using time data supplied from an external time information generator. Furthermore, the present invention relates to a method of controlling such a device or apparatus, method of controlling displaying information, a method of operating such a device or apparatus, a storage medium, and a program.
2. Description of the Related Art
It is known in the art to calibrate an internal clock disposed in an apparatus by using time information supplied from an external device, such as time information provided via the Internet, time information provided using a radio wave, or time information provided by broadcasting (further detailed information may be found, for example, in Japanese Patents Laid-Open Nos. 8-16528 and 2000-131471).
A large number of apparatuses are known which use such time information service. However, most of those apparatuses use time information service simply for the purpose of calibration of their internal clock and do not use time information service in further useful manners.
Nowadays, we have to deal with a great number of pieces of digital information. In dealing with such a large number of pieces of digital information, it is needed to manage the date/time at which each piece of digital information has been produced or changed. When there is a plurality of versions for certain digital data, date/time information is useful to retrieve latest data.
In many apparatuses, the capability of automatically calibrating the internal clock using time information provision service allows a reduction in burdon on users to adjust time. However, there are some problems to be solved in order to achieve higher reliability of date/time information.
Some apparatuses using time information provision service have a capability of allowing users to manually set date/time information used by apparatuses, but some apparatuses do not have such a capability. Even if an apparatus has a capability of allowing a user to manually set date/time, the date/time manually set by the user is not necessarily accurate, because there is a possibility that the date/time is incorrectly set either by mistake or intentionally. Thus, the apparatus operates in a status in which the date/time information cannot be guaranteed, until the date/time is set using time information provision service.
If the time information provision service becomes unavailable for a long period for some reason, there is a possibility that the error of the internal clock of the apparatus becomes too large during that period.
In the conventional techniques, devices are designed simply to achieve high accuracy in controlling the operation of devices. However, in order to properly use such a device designed to operate on the basis of accurate time information using the time information provision service, a user has to have sufficient knowledge of how to use it. Even in such an apparatus, problems can occur if the time information provision service becomes unavailable for some reason (or if the time information provision service is not used although the service is available). In such a situation, a user will be confused about what to do. Devices are not designed taking into account the possibility that such a problem can occur, and devices do not have capability of dealing with such possible problems, which may be solved by disabling some or all of functions of devices during the period in which the time information provision service is unavailable.
The capabilities or functions of devices using time information provision service vary from one device to another. For example, in a case of an image forming apparatus using time information provision service, the design thereof can be made in many ways. For example, in design of an image forming apparatus, a capability of using time information provision service may be simply added to image forming apparatus, or various capabilities of the image forming apparatus may be optimized so that users can user the image forming apparatus in a more convenient manner and so that the image forming apparatus can operate in a more reliable manner. That is it is needed to design devices from the above point of view, to provide devices that can be used by users in more convenient and reliable manners in various environmental conditions.
That is, when a device or a system using time information service is designed, it is needed to more closely analyze the above-described problems that can occur in actual usage of the device, and it is needed to design the device such the above-described requirements are met.